/**
 * 给 zepto 扩展两个方法
 * @returns {*}
 */
$.fn.prevAll = function (selector) {
    var prevEls = [];
    var el = this[0];
    if (!el) return $([]);
    while (el.previousElementSibling) {
        var prev = el.previousElementSibling;
        if (selector) {
            if ($(prev).is(selector)) prevEls.push(prev);
        }
        else prevEls.push(prev);
        el = prev;
    }
    return $(prevEls);
};
$.fn.nextAll = function (selector) {
    var nextEls = [];
    var el = this[0];
    if (!el) return $([]);
    while (el.nextElementSibling) {
        var next = el.nextElementSibling;
        if (selector) {
            if ($(next).is(selector)) nextEls.push(next);
        }
        else nextEls.push(next);
        el = next;
    }
    return $(nextEls);
};